Method of converting hydrogen sulphide into sulphur dioxide



Patented July 31, 1928.

UNITED "STATES I 1,678,630 PATENT OFFICE.

HANS OF CHICAGO, ILLINOIS, ASSIGNOR TO I. G. FABBL NINDUSTRIE AK TIEN- GESELLSCHAFT, OF FRANKFORT-ON-THE MAIN, GERMANY, A CORPORATION OI GERMANY.

METHOD OF CONVERTING HYDROGEN SULPHIDE IN TO SULPHUR DIOXIDE.

Ho Drawing. Application filed May 4, 1925, Serial No. 28,018, and in Germany May 6,4924.

This invention relates to an improved method of converting hydrogen sulphide (H S) contained in fuel gases, into sulphur dioxide (50,), such as in coke oven gas,

a illuminating gas, blast furnace gas, producer gas, etc., for the purpose of cleaning such gases.

Heretofore, and in such cases where the elimination of hydrogen sulphide (H 8) 10 has been based on the absorption of hydrogen sulphide (H S), considerable difficulty and disadvantage has always been encountered, due to the small power of reaction of hydrogen sulphide (H 8).

For this reason attempts have been made to discard the process .of' elimination of hydrogen sulphide (H S) by absorption entirely", and employ processes of converting hydrogen sulphide (H S) into sulphur dioxide-(S0 by oxidation;

:This sulphur dioxide (S0 thus formed is a very much stronger acid and reacts very much easier on other gases and can therefore be eliminated out of the fuel gas with very much simpler means.

In the method described in German patent to Burkheiser, 220,632, class 26d, group 8, he mixed one-third of the fuel gas with air or oxygen and converted the hydrogen o sulphide (H S) of this'one-third A,) of the fuel gas into sulphur dioxide ($0 by loading it over a contact element. The hydrogen sulphide (H S) of the remaining two-thirds of the fuel gas was reduced by mixing it with the first one-third A,) of the fuel which contained the sulphur dioxide (80,), according to the formu a:

40 The catalytic contact or mass) which he used for oxidizing hydrogen sulphide (H,S) consisted of annealed ferric oxide red) i For the reaction:

consisting of ferric oxide (Fe Ofg are saturated with hydrogensulphide S), air is then supplied. The air thus introduced causes the oxidation of the hydrogen sulphide ,(H s).

' With the present improved method it has been found that by proper selection of catalytic contact elements specifically adapted for the pur ose, the oxidation of hydrogen sulphide H S) tatively reached at 200 to 300 C. (392 to 572 F.). These catalytic elements-may be in the form of an alloy in the shape of wire, fabric, etc., an oxide, a salt, or-a coating on metal. a

For this reason it is necessary that the contact elements shall he possessed of two properties essential for the oxidation of the hydrogen sulphide (H s). First the contact elements must have sufiicient chemical aflinity for the hydrogen sulphide (H S), that is, they must have the property of easily entering into new combinations with hydrogen sulphide (H S), and secondly, the contact elements must have the property of transferring very active oxygen.

Elements conforming with the first requirement are the heavy metals such as iron;

nickel, manganese, copper, etc.,.and elements with oxygen transferring properties are -vanadium, tungsten, etc.

By mixing the two. necessary metals in shape of an alloy, or of metal chips, or metal can be quantioxides or metal.sa1ts,, a contact element can be produced possessing the two required properties. In selecting the proper contact elements ecial care is to be taken that these contact e ements react on the hydrogen sulphide (H S) at as low. a temperature as possible and in doing so will not cause any simultaneous reactions on the remaining gases.

In using for the oxidation of-hydrogen sulphide (H S) a contact element consisting of nickel and tungsten, or nickel and vanadium, or iron and tungsten, or iron and vanadium, the quantitative conversion of hydrogen sulphide (H 8) into sulphur dioxide (S0 300 C. (392 to 572 F. during which selective oxidation process t e ammonia will re main in the gas witho t being exposed to the danger of being disintegrated, the scontainmg the ammonia being produce preferably from any dry distillation of coal, or from any other suitable source.

The gen necessa for the formation of sulphur ioxide (SO will be supplied to 5 the gas by a small addition of air; 'at any gen sulphide (H S).

The higher temperature necessary for the performing of the reduction may be attained either by direct heating (electrical current through contact element) or indirect heating of the contact element, or also by heating ties of the the gas. The direct heatin of the contact element has the advantage that it is possible to easily remove from time to time the tar substances which form part of the impurigas and settle on the contact elements. v V

It is only necessary toturn on air and increase the electric current whereby the tar particles will burn ofl. Obviously any other suitable form' of heating may be resorted to.

What is claimed as new is 1. The method of converting hydrogen sulphide of gases into sulphur dioxide for the purpose of the gases by the emp oyment of contact elements necessary for the oxidation, one of said elements embodying a mixture of metals having the property of binding sulphur, and an element embodying metals transmitting oxygen.

2. The method of converting hydrogen sulphide of gases into sulphur dioxide for the purpose of purifying the gases by the emp oyment of contact elements necessary for the oxidation consisting of a mixture of metals having the property of binding sulphur, such metals being of the class of metals which includes iron, nickel, copper or the. hke, and metals transmitting oxygen, such latter metals being of the class which includes vanadium, V 11. I

3. The method of converting hydrogen sulphide of gases into sulphur dioxide for the purpose of purifying the gases by the. employment of contact elements necessary for the oxidation consisting of a mixture of metals. having the property of binding sulphur, such metals being of the class of-metals which includes iron, nickel, copper or the like, .and metals transmitting oxygen, such latter metals being of the which includes vanadium, t ten, the catalytic elements being in the orm of an alloy in a' for the oxidation consisting of a mixture of metals having the property of binding sulphur, such metals being of the class of metals which includes iron, nickel, copper or the like, and metals transmitting oxygen, such latter metals being of the class of metals which includes vanadium, tungsten, the catalytic elements-being fixed on bodies having large surfaces V 5. The method of converting .hydrogen sulphide of gases into sulphur dioxide for the purpose of the gases by the employment of ntact elements necessary for the oxidation consisting of a mixture of metals having the property of, binding-sul- I phur, such metals being of the class of metals which includes iron, nickel, copper or the like, and metals transmitting oxygen, such latter metals being of the class of metals which includes vanadium, tungsten, the catalytic elements being heated.

6. The method of converting hydrogen sulphide of gases into sulphur dioxide for the purpose'of purifying the gases by the employment of contactelemcnts necessary for the oxidation consisting of a mixture of metals having the property of binding 'sulphur, such metals being of the class ofmetals whichincludes iron, nickel, copper or the like, and met-alstransmitting' oxygen, such latter metals being of the class of metals which includes vanadium, tungsten, the gas being heated.

' 7. The method of converting hydrogen sulphide ofgases into sulphur dioxide for the purpose of purifying the gases by the employment of contact elements necessaryfor the oxidation consisting of a mixture of metals having the property of binding sulphur, such metals being of the class of metals which includes iron, nickel, copper or the like, and metals transmitting oxygen, such latter metals being of the class of metals which includes vanadium, tungsten, the gasbeing submitted to reduction before the removal of ammonia therefrom.

In testimony whereof, I have signed my name to this specification, on this 29th day of April, A. D. 1925.

HANS BKHR. 

